Halide leak detector



0d. 8, 1957 H A, MITCHELL Y 2,809,101

' HALIDE LEAK DETECTOR Filed' May 5. 1954 si.. s e ri r einigte HALIDE LEAK DETECTOR Harry Albert Mitchell, Sycamore, Ill., assignor to The Turner Brass Works, a corporation of Illinois This invention relates to a device for detecting gases and more particularly to an improved halide leak detector.

In the use of refrigeration equipment utilizing a halide refrigerant such as Freon, it is often desirable to test for possible leakage of the refrigerant into the atmosphere. A frequently used method is a llame test, which the present invention embodies, in which a sample of the atmosphere to be tested is introduced into the detector through a search hose and mixed with the combustion gas. The gas llame impinges on a heated reaction material, such as copper, causing a characteristic change in the color of the llame if halides are present.

lt is desirable to keep the llame small in order to detect slight color changes therein when there i-s a low concentration of halides, but also to have adequate suction to ensure drawing in the sample of the atmosphere to be tested, which ordinarily requires a relatively large llame. Accordingly, an object of this invention is to provide a rates Patent hice new and improved llame-type halide leak detector having means for creating a greater suction through the search hose for size of flame than heretofore known.

Another object of the invention is to provide a new and improved halide` leak detector operable in any direction without changing the grip of the operator thereon comprising a search hose connected to the burner apparatus by a swivel connection allowing the hose to be easily swung around the burner apparatus for use in all directions without destroying the suction in the hose.

Another object of the invention is to construct the burner assembly of a leak detector utilizing liquid petroleum gas with a secondary ilame surrounding the primary i flame to ensure constant burning thereof.

Another object is to provide a halide leak detector embodying a burner tube assembly releasably connectable to a portable fuel tank and having a longitudinal gas bore forming at one end part of a circular secondary flame burner surrounding a primary llame burner means in the gas bore, a reactor member operably positioned over the primary llame, a cylindrical collar and :attached search hose rotatable around the burner tube, the collar and adjacent periphery of the tube forming an annular passage communicating with the search hose and radial openings in the burner tube which open to the gas bore, the search hose being operable to introduce into the gas bore by suction a sample of the atmosphere to mix with unignited fuel gas llowing through the bore, the mixture burning in a llame which reacts with the heated reactor member to change color when the mixture contains a halide.

Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

Fig, l is a front elevation, partially in vertical section, and illustrating the preferred form of the invention;

Fig. 2 is an enlarged horizontal sectional view taken along line 2--2 of Fig. l and illustrating the primary and secondary burner means; and

Fig. 3 is an enlarged horizontal sectional view taken 2,809,10l Patented Get. 8, 1957 along line 3-3 of Fig. 1, and illustrating the rotatable collar and associated passages.

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail an illustrative embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplication of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Referring now to Fig. l of the drawing, the preferred form of leak detector is lshown releasably connected to a disposable fuel tank by any suitable valve assembly 11 provided with a control knob 12 connected to the valve member for regulating the flow of fuel gas through the leak detector burner tube assembly 13 which is releasably connected at its lower end to the valve assembly 11.

The burner tube assembly comprises a lower extension tube 14 having a through longitudinal bore 15 communicating at one end with the valve 11. A filler rod 16 is positioned in the extension tube with its outer periphery in a slightly spaced relation from the inner periphery of the extension tube 14 to provide an annular gas passage through the extension tube. The filler rod 16 is shorter than the tube 14 to permit the insertion of an orifice block 17 in the bore 15. The orifice block 17 is provided with a bore 18 and has an enlarged head 19 providing a shoulder 20 which rests on the end of the extension tube 14.

A cylindrical primary tube 22 forming part of the burner tube assembly is threadably received on the end of the extension tube 14 and has a longitudinal bore 23 communicating with the orifice block bore 18 and is provided with a lower cut away portion 24 which iits snugly around the oriiice block head 19 to hold the orifice block in position in the extension tube 14. The lower portion 25 of the primary tube 22 is hexagonal in shape and has an upper surface forming a shoulder 26 around the outer periphery of the tube sloping outwardly and downwardly. The upper portion of the primary tube 22 is threadably received in the lower end of a burner cooling adapter member 27 of the burner tube assembly which is provided with a plurality of external radial air cooling iins 28. The adapter member 27 has a longitudinal bore 29 communicating at one end with primary tube bore 23 andl opening at the-other end to the burner end of the burner tube assembly 13.

Novel burner means, to be subsequently described, are positioned in the end of the tube assembly 13 and cause a llame to impinge against a copper glow reactor ring 30. The reactor when heated by a flame produced by combustion of a mixture of fuel gas from tank 1t) and a sample of the atmosphere introduced into the bore 23 by a search hose 21 reacts with the flame and in the presence of a halide gas in the mixture causes a characteristic change of color in the iiame. The reactor ring 30 is provided with a cylindrical opening 31 through which the Vllame passes and is carried by an L-shaped stamping 32 detachably secured to a cylindrical open-end shield 33. The shield 33 rests upon an asbestos washer 34 supported by a rib 35 on the adapter member 27 and is securely held in place by a nut 37 threaded on the upper end of the adapter member 27. A window 38 in the shield 33 permits observation of the llame emitting from the reactor ring 30.

The burner means positioned in the upper end of the adapter member 27 provide a primary llame which is the principal testing flame and a secondary flame surrounding the primary flame which functions as a pilot flame to maintain the primary llame and also aids in heating the reactor ring 30. Such a pilot flame has been found necessary where the fuel is in the form of a liquid petroleum gas. A cylindrical burner insert 41 is positioned in the end of the adaptermember 27 and has a lower portion 42 in substantially gas tight engagement witha peripheral portion of the bore 29 and seated on an internalV shoulder 4t) in the adapter member. An upper portion 43 of the insert 41 extends to a position slightly below the end of the adapter member 27 and is spaced from the inner periphery thereof to form therewith an annular recess 44 for use as a secondary burner which emits the pilot ame. The insert has a central bore 45 and a smaller opening 46 communicating with bore 45 and concentric within annular recess 44` to provide the burner which emits the primary ame. As best shown in Fig. 2, four'radial passages 47 areequally spaced about the periphery of the insert 41 and connect the bore 45 with the lower portion of annular recess 44` so that a portion of the combustion mixture may enter the recess.

The search hose comprises'a' rubber hose section 50 tightly fitted around the end of a flexiblemetal hose 51 connected to a brass member 52 which is threadably received by a port 53 in a cylindrical collar 54.

Novel means are provided intermediate the ends of the burner tube assembly. 13 for providing a rotatable connection allowing the search hose 21 to be. swung around the burner tube for ready use in any direction and causing maximum suction in. the hose. The collar 54 is provided with a groove 55 intermediate its ends forming annular ribs 56 at its ends which are rotatable on a peripheral portion of the primary tube 22. An asbestos gasket S and a -similar asbestosvgasket 59 bearing on a brass washer 61 act to substantially seal the collar to the primary tube 22 in order to maintain suction through the hose 21. The collar and gasket are held in place on the primary tube by the adapter member 27.

Communication between the groove 55 and primary tube bore 23 is established by six radial equi-spaced cylindrical passages 57 extending through the primary tube wall, as best shown in Fig. 3. It has been found that this construction provides a suction through the search tube greater per size of detecting flame than heretofore known in the art, thus ensuring that an adequate sample of the atmosphere will be drawn through the search hose 21 to mix with fuel gas ilowing through the burner tube from tank when the detector isoperating with a relatively small ame.

I claim:

1. A halide gas leak detector for detecting the presence of halides in a gas mixture provided with means forming a burner tube assembly having a longitudinal bore, a burner opening at one end ofthe tube and means at the other end for receiving fuel gas from a source connectable thereto, an insert positioned in the burner end of the bore and having a portion in tight engagement with the periphery thereof and a portion spaced therefrom to form an annular recess for use as a secondary tlame burner, means defining an axial bore in the insert and an opening communicating with said insert bore for use as a primary flame burner positioned within the connes of the secondary llame burner, means defining a plurality of radial passages communicating between the insert bore and the annular recess to allow ow of gas from the bore into said annular recess, reactive means disposed above the insert operable to cause a color change in the ame if a halide is present in the gas mixture, a spaced pair of shoulders disposed around said tube intermediate the ends thereof, a cylindrical collar having a groove on its inner periphery freely rotatably disposed on said tube and between said shoulders, spacer gaskets disposed between said collar and said shoulders, the groove in said collar forming with the tube an annular passage for receiving a sample of the atmosphere, a plurality of radial passages in the tube communicatingbetween the annular passage and the tube bore, and an inlet port in said collar communicating with the annular passage and having a flexible hose releasably connected thereto for introducing into the passage a sample of the atmosphere to mix with unignited fuel gas flowing through the tube bore.

2. A halide gas detector comprising: means defining a burner tube assembly including av primary tube and having a longitudinal bore with an opening at one end of the tube assembly for receiving a burner means and an opening at the other end for receiving fuel gas from a source, burner means in said one end of the tube providing a central primary flame opening and an annular secondary flame opening surrounding said central flame opening, a cylindrical collar surrounding and freely rotatably mounted on the primary tube intermediate the ends thereof, said collar having a circumferential groove on its inner face and defining with a portion of the outer periphery of the primary tube an annular passage, the primary tube having a bore forming part of said longitudinal bore and a plurality of spaced radial passages extending through its wall to connect the annular passage and the assembly bore, means on said tube assembly on either side of saidcollar for preventing longitudinal movement thereof alongthe primary tube, means sealing said collar to thek adjacent part of the tube to prevent leakage around said collar, said collar having an inlet port leading to said annular pas-sage and means connected to the inlet port for introducing through said passage into the bore a sample of the atmosphere to be mixed with fuel gas liowing through the bore from the source toward the burner means, and reactive means disposed adjacent said burner means and adapted to cause a color change in the flame if a halide is present in Isaid sample of atmosphere.

References Citedfin the file of this patent UNTED'STATES PATENTS 1,645,294 Rodman Oct. 11, 1927 2,134,552 Gaugler Oct. 25, 1938 2,200,523 Tuel May 14, 1940 2,237,889 Rickert Apr. 8, 1941 2,272,593 Andrle Feb. 10, 1942 2,758,917 Popp Aug. 14, 1956 FOREIGN PATENTS 678,806 Great Britain Sept. 10, 1952 OTHER REFERENCES Schaar: Selected Laboratory Equipment Catalog, No. 50, copyright 1950, page 99. 

2. A HALIDE GAS DETECTOR COMPRISING: MEANS DEFINING A BURNER TUBE ASSEMBLY INCLUDING A PRIMARY TUBE AND HAVING A LONGITUDINAL BORE WITH AN OPENING AT ONE END OF THE TUBE ASSEMBLY FOR RECEIVING A BURNER MEANS AND AN OPENING AT THE OTHER END FOR RECEIVING FUEL GAS FROM A SOURCE, BURNER MEANS IN SAID ONE END OF THE TUBE PROVIDING A CENTRAL PRIMARY FLAME OPENING AND AN ANNULAR SECONDARY FLAME OPENING SURROUNDING SAID CENTRAL FLAME OPENING, A CYLINDRICAL COLLAR SUROUNDING AND FREELY ROTATABLY MOUNTED ON THE PRIMARY TUBE INTERMEDIATE THE ENDS THEREOF, SAID COLLAR HAVING A CIRCUMFERENTIAL GROOVE ON ITS INNER FACE AND DEFINING WITH A PORTION OF THE OUTER PERIPHERY OF THE PRIMARY TUBE AN ANNULAR PASSAGE, THE PRIMARY TUBE HAVING A BORE FORMING PART OF SAID LONGITUDINAL BORE AND A PLURALITY OF SPACED RADIAL PASSAGES EXTENDING THROUGH ITS WALL TO CONNECT THE ANNULAR PASSAGE AND THE ASSEMBLY BORE, MEANS ON SAID TUBE ASSEMBLY ON EITHER SIDE OF SAID COLLAR FOR PREVENTING LONGITUDINAL MOVEMENT THEREOF ALONG THE PRIMARY TUBE, MEANS SEALING SAID COLLAR TO THE ADJACENT PART OF THE TUBE TO PREVENT LEAKAGE AROUND SAID COLLAR, SAID COLLAR HAVING AN INLET PORT LEADING TO SAID ANNULAR PASSAGE AND MEANS CONNECTED TO THE INLET PORT FOR INTRODUCING THROUGH SAID PASSAGE INTO THE BORE A SAMPLE OF THE ATMOSPHERE TO BE MIXED WITH FUEL GAS FLOWING THROUGH THE BORE FROM THE SOURCE TOWARD THE BURNER MEANS, AND REACTIVE MEANS DISPOSED ADJACENT SAID BURNER MEANS AND ADAPTED TO CAUSE A COLOR CHANGE IN THE FLAME IF A HALIDE IS PRESENT IN SAID SAMPLE OF ATMOSPHERE. 